Find the measure of angle A

Which term best describes the association between variables a and b? no association a negative linear association a positive linear association a nonlinear association a scatterplot with an x axis labeled, variable a from zero to ten in increments of two and the y axis labeled, variable b from zero to one hundred forty in increments of twenty with fifteen points in a positive trend.

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Me. i can't figure out this question. give an explanation too. .